• Journal of Biosystems Engineering
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• v.24 no.2
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• pp.145-152
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• 1999

Methods of discharging each graded agricultural product are divided into two according to the type of feeding. One is based on feeding objects using a series of specially designed holders mounted with an equal interval. The other is randomly feeding objects while being isolated without a specific interval. In this paper, a real time simultaneous discharge algorithm, which is good for objects randomly fed individually and for multi-objects located along a series of discharge buckets, was developed. And the developed algorithm was implemented to the controller and the performance was verified using the system developed for dried mushrooms. The discharge system used for the experiment was composed of a variable speed conveyor, a series of double channel bucket mounted along both sides of the conveyor, and a series of air nozzles and optic sensors. Developed algorithm worked perfectly and could be directly used for automatic discharge system for randomly feeding agricultural products.

• Journal of Biosystems Engineering
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• v.31 no.5 s.118
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• pp.416-422
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• 2006

Drying characteristics of green onion and onion during fluidized and fixed bed drying were investigated and compared. Sliced peen onion and onion were dried at drying air temperature of 45, 55, and $65^{\circ}C$. Drying air velocity during fluidized bed drying was adjusted with drying time at each drying temperature. Drying time to reach a given final moisture content was shorten in fluidized bed drying than in fixed bed drying - for drying temperature of 45, 55, and $65^{\circ}C$, the differences were 60, 60, and 50 min for green onion and 360, 180, and 60 min for onion. Drying constant (K) was greatly affected by drying method and drying temperature. Terminal velocity under fluidized bed drying was decreased exponentially for green onion and linearly (or onion with increase of drying temperature. Also, terminal velocity had linear relationship with moisture content for both green onion and onion.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.477-484
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• 2017

This study was conducted to investigate the content of sulfur dioxide, carotenoids and the degree of contamination of Bacillus cereus in 33 kinds of dried sweet potato from domestic mainly dried agricultural products in Korea. According to the characteristics of dried sweet potato samples, it was classified into four clusters and as a result of analyzing the contents of sulfur dioxide, carotenoids and the degree of contamination B. cereus was no significant difference among the clusters. The detection ranges of residual sulfur dioxide from 33 dried sweet potatoes ranged from 0.38 to 28.16 mg/kg, three cases (9.09%) were detected at the reference level of 10 mg/kg or more. But no samples exceeding 30 mg/kg, the tolerance level of sulfur dioxide in dried sweet potatoes were detected. Since dried sweet potato does not have a standard for carotenoids, when comparing the national and international standards of carotenoids, the range of detection of carotenoids in dried sweet potato was $46{\sim}2,663{\mu}g$/100 g, which was within the reference range of $0{\sim}9,826{\mu}g$/100 g. In principle colonies suspected to be B. cereus in dried sweet potato were not detected. In 7 cases (21.21%), there were detected in the range of 0.05~1.59 log CFU/g but not more than 3 log CFU/g as the reference value. The results of this study are expected to be used as basic data to establish quality standard for dried sweet potatoes. In order to control the quality of dried sweet potatoes in domestic market, raw materials, drying method and packaging after distribution, it is necessary to maintain and maintain the process steadily.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.1092-1098
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• 2012

Aroma compounds in sun-dried salt according to saltern material and packaging box were extracted by the headspace and were isolated by using GC-MS. These compounds were identified including ketones, heterocyclic compounds and six other compounds. Major aroma compounds in salts were identified as 4-methyl-2-pentanone, 5-methyl-3-hexanone, 4-methyl-3-penten-2-one, 2-hexanol, benzothiazole, 2,4-bis(1,1-dimethylethyl)-phenol, and 1,3,5-tri-tert-butyl benzene. However, we found no significant differences according to the saltern materials in three salts. Salts stored in Chamaceyparis obtusa (Sieb. et Zucc.) had more diverse aroma profiling than those in Pinus densiflora and Paulownia coreana. We consider that it need to research the development of high value added products for new aromatic salt.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.5
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• pp.1082-1086
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• 1999

Dried vegetables, white ginseng and spices, which were exposed to gamma and electron beam irradiation, were used in a detection study by measuring their starch content and viscosity change. The samples tested showed different levels of starch content(15.64~60.86%), which was not directly proportional to the viscosity of the samples. The correlation coefficients between irradiation dose and viscosity change were lower in the samples, such as cabbage, carrot, clean vegetable(chunggyungchae), garlic, mushroom, green onion, and red pepper, while some higher coefficients were found in ginger(R2=0.9271), white ginseng (R2=0.6223) and onion (R2=0.7909). Thus, dried ginger and white ginseng were selected to be used for a detection of irradiated samples using specific parameters(threshold values). Specific parameter for the nonirradiated ginger and ginseng were 13.31 and 13.93, respectively. On the other hand, gamma and electron beam irradiated samples at 2.5 kGy, the lowest dose for a commercial purpose, showed decreased values, 11.92 and 11.15 in ginger, and moreover 4.40 and 5.10 in ginseng. It is expected that a proportional decrease in a specific parameter with the absorbed doses will be a potentially useful index for detecting whether starchy foods have been irradiated or not.

• Journal of the Korean Wood Science and Technology
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• v.52 no.1
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• pp.70-86
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• 2024

Termites are a serious threat to wood-based products in Indonesia. This study investigated the termite resistant property of glulam made from polystyrene-modified wood. Three tropical fast-growing wood species, namely mangium (Acacia mangium), manii (Maesopsis eminii), and rubberwood (Hevea brasiliensis), were prepared for flat-sawn laminae. After getting air-dried condition, the laminae were impregnated with polystyrene using potassium peroxydisulphate as a catalyst followed by polymerization at 80℃. Polystyrene-impregnated and control glued-laminated lumbers (glulams) were manufactured, and solid wood was provided. Three wood species and three wood products with six replicates were exposed in a field in Bogor, Indonesia, for four months, and before the tests, their density and moisture content were measured. At the end of the field tests, the weight loss and protection levels of each test sample were determined. A completely randomized factorial design was used for data analysis. The weight percentage gains for mangium, manii, and rubberwood were 22.30%, 18.22%, and 10.44%, respectively. The results showed that manii belonged to low-density wood, whereas the other two woods were medium-density wood, and the moisture content was the ambient moisture content, typical of the Bogor area. Regarding weight loss and protection level, mangium was the most durable against subterranean termite attacks, followed by rubberwood and manii. Among the wood products, the polystyrene-impregnated glulam presented the highest durability, followed by the control glulam and solid wood. Therefore, mangium and rubberwood polystyrene-impregnated glulams are recommended for future product development.

• Journal of Korean Society of Forest Science
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• v.107 no.4
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• pp.422-427
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• 2018

This study was performed to determine quality characteristics of solar-dried persimmon for each cultivar. The physical and sensory characteristics of 4 cultivars of solar-dried persimmons (Gojongsi, Godongsi, Sangjudungsi, Koshuhyakume) were investigated. As a result, yield rate and firmness was highest in Koshuhyakume (29.5%, 9.62 N). Meanwhile, the soluble solid content (SSC) was the highest in Gojongsi ($27.3^{\circ}Brix$) and it has a significant difference between 4 cultivars (p<0.05). The water activity was range from 0.784 to 0.819 and Gojongsi (0.784) was significantly lower than others. The water contents value was the highest in Koshuhyakume (37.51%), while Sangjudungsi (35.32%) was the lowest. In case of Hunter's value, 'L', 'a' and 'b' were the highest in Sangjudungsi (34.56, 9.24, 17.07), whereas Koshuhyakume (29.17, 5.68, 13.59) has generally low value. In sensory evaluation, overall acceptability was the highest in Gojongsi and Godongsi (5.16), while Koshuhyakume (3.95) was the lowest. The results showed that the quality characteristics of dried persimmon manufactured by solar drying method have distinct difference according to cultivars.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.3
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• pp.41-49
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• 2005

Styrofoam as shock-absorbing materials for packaging has been regarded as one of non-biodegradable products leading to soil contamination at a landfill and release of dioxine during its incineration. For avoiding severe burdens on our environments by styrofoam, it must be replaced by environment-friendly materials. In order to evaluate availability of pulp fibers as a substitute for styrofoam, various extrusion processes were applied for making optimal biodegradable products. Then thermomechanical pulp fibers made of Pinus radiata and Pinus rigida were uniformly mixed with other additives such as starch and polyvinyl alcohol prior to expansion. The physical properties of the final products were examined by measuring expansion efficiency, compression strength, and elastic modulus. Wheat starch played a key role to maintain optimal flowing conditions within the barrel of the extruder irrespective of addition of soluble starch and polyvinyl alcohol. However, as the amounts of wheat starch in raw-materials increased, the elastic modulus of the expanded materials greatly increased. High elastic modulus is not suitable as shock-absorbing products for packaging. Thus the wheat starch must be added at a minimum if possible, that is, below 20% based on oven-dried weight of pulp fibers. the elastic modulus of the expanded products was decreased as their moisture contents increased. For the products containing 20% wheat starch, the lowest elastic modulus, 844.64 kPa was obtained under 10% of the moisture content. This was similar to that of styrofoam.

• Korean Journal of Medicinal Crop Science
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• v.27 no.3
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• pp.186-193
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• 2019

Background: Astringent persimmon (Diospyros kaki Thunb. cv. Kojongsi) peels are by-products of dried persimmons. This study aimed to evaluate the antioxidant activities of Kojongsi persimmon peel (KPP) extracts prepared by 15 different extraction methods: 5 heating durations (0.5 - 2.5 h) at 3 heating temperatures (50, 70, and $90^{\circ}C$). Methods and Results: An increase in heating temperature increased the antioxidant effect of KPP extracts. Those prepared by heating at 1 h had the highest total phenol content, regardless of the heating temperature. In addition, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and cell-protective effects against $H_2O_2-induced$ oxidative stress were dependent on the total phenol contents of the extract. However, the KPP-induced increased in catalase expression was dependent on heating temperature and duration. Conclusions: These results suggest that extraction by heating at $90^{\circ}C$ for 1 h may enhance KPP's antioxidant effects, which mainly involve non-enzymatic antioxidant systems.

• Journal of the Korean Wood Science and Technology
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• v.44 no.2
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• pp.172-183
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• 2016

Densification of the inner part of oil palm trunk (OPT) by the close system compression (CSC) method was performed in this study. The effects of the compression temperature and time on the anatomical, physical and mechanical properties of OPT were evaluated. The inner part of OPT with an initial average density of $0.3g/cm^3$ was used as samples. Oven-dried samples were immersed in water and vacuumed until fully saturated and then compressed by CSC at 120, 140, 160 or $180^{\circ}C$ for 10, 20, 30 or 40 min. The anatomical characteristics of transverse and radial sections before and after compression were compared by optical microscopy. The physical and mechanical properties, including the density, recovery of set (RS), modulus of elasticity (MOE), modulus of rupture (MOR), and compression parallel to grain were examined. It was observed that the anatomical characteristic of the inner part of OPT (i.e., vascular bundles, vessels, and parenchyma tissue) became flattened, fractured, and collapsed after compression by CSC. The RS decreased with increasing compression temperature and time. The lower RS indicated high dimensional stability. The physical and mechanical properties (i.e., density, MOR, MOE, and compressive strength) of the inner part of OPT increased with increasing compression temperature and time. Compression by the CSC method at $160^{\circ}C$ for 40 min was the optimum treatment.